Move makes high-stakes matchup likely between former U.S. Surgeon General Richard Carmona and Rep. Jeff Flake

Former Arizona Democratic Party Chair Don Bivens dropped his U.S. Senate bid this week and urged voters to unite behind the campaign of former U.S. Surgeon General Richard Carmona, a Tucson surgeon.
The move means Carmona has a lock on the Democratic nomination for what should turn out to be one of the nation’s most hotly contested Senate seats, with control of the U.S. Senate potentially hanging in the balance.